Inking device for rotary duplicating machines



July 2o, 194s. F. ELLAM' 2,445,666

I n INKING DEVICE FOR ROTARY QDUPLICTI NCT v-MACIIIIES Filed Aprila?, 1946 Patented July 20, 1948 `minne DEVICE Fon no `ivniclnuns TARY DUPLICATING Frederick Bharu, Watord, England .Application April n, 1ste, serial No. 662,831 In Great VBritain Maly 4, 1945 vThis invention relates to vduplicating machines of the kind having a rotatable perforated metal cylinder covered peripherallywithan in-kng cloth over which is secured a stencil of matter to Vbe duplicated, In such machines, it lis usual vto charge the cylinder interiorly with a layer of ink and -to force the ink through the perforatons in the cylinder into the cloth covering, whence 'it passes, as the cylinder is rotated, through the stencil and on to sheets of paper, the forcing of the ink through 'the perforations in the cy1- inder ybeing effected from time to time by means of an inkl-ng roller disposed within the cylinder land arranged to be advanced radially against the inner periphery of the cylinder. Suchy an arrangement has the disadvantage that immediately after the inking roller has been used the duplicated copies `wil-l be heavily inked and succeeding copies Awill 'be paler and paler vuntil the inking roller is used again, and so on. In some cases, however, the inking roller is inaction con.- tinually. A disadvantage of either of these sys tems is that after some time the inkcharged into the cloth cover Works to the trailing .end and, to some extent, to the -sides thereof and 'tend-s to soil the copies produced, and there is a tendency of the ink to become contaminated with particles which disintegrate .from the surface .of the ink.- i-ng roller. A still further disadvantage is that, after a large number .of copies has 'been produced Afrom a stencil of such a nature that onlya portion is `used Vfor duplicating purposes, the remain.. der being blank, that 'partl of .the cloth which cor'- responds with the blank becomes .over-inked, with the result that when the stencil is removed and replaced by another stencil onwhich the wording occupies the whole sheet, it is impossible to get an evenly balanced copy, even after running oi hundreds of copies, and the only satisfactory solution is to change the inking cloth. :Such disadvantages are .obviated .by the pres'- ent invention which is intended to .charge the `perforated cylinder and the cloth cover lcontinuously but only with substantially that quantity of ink which will be required per revolution of the cyl!- inder.

'The invention consists 'in ink-feeding means .for a rotary duplicating machine of the-'kind described, comprising a trough disposed within the perforated cylinder, the trough being closed'. ex- I cylinder opposite the open side: ofthe trough, Y

13 llams, (Cl. 10J- 119) while 4the trailing edge of the trough '(i. e; that .edge over which any'zpart ofthe cylinder passes last as it moves away from the trough) is ar ranged to remove superfluous in'k from the inner yperiphery of the zcylinder and -retain it Lin the trough. In consequence of this arrangement, `ifi-lc is -fed constantly 'to any Apart of the perforated cylinder which, for 'the' time being, cis oppsite the open side of lthe trough, Abut practically all ink is removed from the inner periphery offA the cylinder asv it moves away `from the "trough, leave i-ng', Ito pass 'to the :cloth cover, `oniy such amount as is contained in the perforatiens themselves; hence all duplicated copies will die of the `same density.

The `-tra`,-ilir'1g edge of the trough may constitute a doctor-blade for the rremoval of superfluous ink, 4or the trailing wall may be provided -witha spring-urged radially outwards against the riphery of the cylinder.

In order to cut orf the flow ofV link when .the machine is standing idle, the trough mayV be movable about the -axis of the cylinder, its idle posi vtion being at the top of the cylinder, i. =e its open side directed upwards, and its operative pe- -sition being at about to 'its idle position, i. Ve. with its open side directed towards .one sideof the cylinder, so that the cylinder then constitutes a retaining wall for the ink, which, however, passes by gravity into .the perforations during such time as any particular part of the cylinder is; acting as ink-.retaining wall.

The' change of position of the trough from its inoperative position to its operative position-and vice versa may `be eected positively by means aotuatedf-rom outside the cylinder. Alternatively, the trough may be carried 'by a counterbaiancedor spring-iniiuenced arm, the arrangement being lpin-ely automatic ein that Iwhen :theieylinder -is rotated the friction 4between it and the `trough will` carry round the flatter .to its' operative position and, when rotation of the .cylinder ceases, the trough will return :to its inoperative position under-the influence of itscounterweight orspring.

@ne form of the infs'ention` will be described with reference to the drawings, in which:

\ Figure 1 is a partly sectioned side velevation of a'cylinder of a rotary duplicating machine;

Figure 2 is asection on the line 2--2, Figure. l;

Figure 3 is a broken' perspective: viewon a smaller scale, showing :ink-feedingr means in the idle position; `and Figure 4 is a` similar view showingA the ,inkfeeding means in .the operative posi-tion. .Referringy toA Figures 1 and 12, a' cylinder 1Q clined towards the lea-ding edge and is in contact with the cylinder so as to scrape its surface whenv said cylinder is rotated.

The shaft I2 extends through the ends Il and is carried in bearings (not shown) to support the cylinder, and at one end carries an arm I8 fixed to said shaft. As the arm I3 and the arms I4 which carry the trough I5 are all fast on the shaft I2, the trough may be turned from the position shown at I5 (Figures 2 and 3) to that shown at 45a (Figures 2 `and 4), and this movement is limited by stops 'i9 Yand 20 (Figure 2), which are mounted onor integral with a stationary part of the duplicating machine.V 4When the duplicating machine is not in use, the trough ismaintained in the idle Vposition shown at I5, and the ink is` kept out of contact withl the cylinder I0, and therefore no overchargingof theinking-cloth can occur.

When the cylinder IIJ is to be rotated for the purpose of duplicating, the arm i8 is moved from its vertical position to its horizontal position against, the stop 2U, and the trough is thereby moved tothe position indicated at |58. Thus, the ink is allowed access to that portion lof the periphery of the cylinder which extends between the trailing and leading edges of the trough, and fills the perforations|3. When the cylinder is rotated, the trailing edge, indicated at I1, wipes from the cylinder all the ink except that actually in the perforations, and the process is repeated for the next portion of the periphery to be exposed to the trough. Continuous rotation of the cylinder, therefore, results in the perforations being charged as they pass the trough, and the inking-cloth receives a steady supply. After kuse,'the arm I8 is rotated to abut against the .stop I9, thus-returning the trough I5 to its idle position. l,

vInasmuch as the trailing `edge I'I of the trough I5 removes all superuousink and retains it in the trough it follows that after use the interior of the perforated cylinder Iii will be clean as compared with. a cylinder into which ink has been charged inthe manner heretofore usual, hence, when using quick drying emulsion inks -the effects ofany tendency of residual ink to vadvantageously be constituted by an extension on either or both of thearms I4 vwithin the cylinder and, by selection of a suitable counterweight, the'friction between the trailingedge of the trough and the innerperiphery of the cylin- :der maybe utilized to bring about automatic all movement of the trough into the operative position on rotation of the cylinder.

Alternatively, a counterweight may be mounted externally of the cylinder, as on an extension on the arm I8, and stops may be provided on a xed part of the machine to limit the travel of the trough to the sector defined by its idle and operative positions.`

I claim:

1. A rotary duplicating machine having a supporting frame, a horizontal spindle carried thereby, a metal cylinder formed with perforations and rotatably mounted on the spindle, an inking cloth covering said cylinder peripherally and arranged to receive a stencil of matter to be duplicated, radial arms pivotally mounted on the spindle within the ends of the cylinder and movable independently of the rotation of the cylinder, a trough carried by the arms within the cylinder and having walls xed relatively to one another, the Vtrough being open at the side directed towards the inner periphery of the cylinder, those walls directed towards the inner periphery fitting closely V against said periphery, and means for moving said trough from an idle position in which the radial arms Iare vertical and the walls4 of the trough retain any ink in said trough out of contact with the inner periphery of the cylinder, to an operative position, in which the pivoted arms are maintained in a substantially horizontal position, and in which said ink is heldin the trough with direct access to the inner periphery of the cylinder by gravitational flow into the perforations therein, providing a continuous and even charge of ink to the cylinder during its rotation.

2. A rotary duplicating machine having a supporting frame, a horizontal spindle carried thereby, a metal cylinder formed with perforations and rotatably mounted on the spindle, an inking cloth covering said cylinder peripherally and arranged to receive a stencil of matter to be duplicated, radial arms pivotally mounted on the spindle within the ends of the cylinder and movable independently of the rotation of the cylinder, a trough carried by the arms within the cylinder and having walls fixed relatively to one another, the trough being open at the side directed towards the inner periphery of the cylinder, those walls directed towards the inner periphery-fitting closely against said periphery, and meansexternal of the cylinder for moving said trough from an idle position, in which the radial arms are vertical and the walls ofthe trough retain anyink in said trough out of contact with the inner peripheryof the cylinder, to an operative position, in which the pivoted arms vareV maintained in a substantially horizontal `cloth covering saidcylinder peripherally and arranged-tov receive. a stencil of matter to be duplicated, radial arms pivotally mounted on the spindle -within the ends of the cylinder and movable independently of the rotation of the cylinder, a trough carried by the arms within the cylinder and hav- 5 ing walls fixed relatively to one another, the trough being open at the side directed towards the inner periphery of the cylinder, those walls directed towards the inner periphery fitting closely against said periphery, the trailing edge of the trough being arranged to constitute a doctor blade, and means for moving said trough from an idle position, in which the radial arms are vertical and the walls ,of the trough retain any ink in said trough out of contact with the inner periphery of the cylinder, to an operative position, in which the pivoted arms are maintained in a substantially horizontal position, and in Which said ink is held in the trough with direct access to the inner periphery of the cylin- 15 2,333,332

der by gravitational now into the perforations therein, providing a continuous and even charge of ink to the cylinder during its rotation.

FREDERICK ELLAM.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 762,165 Hainey June 7, 1904 1,527,783 Braseur Feb. 24, 1925 2,276,181 Foster Mar. 10, 1942 Kent Nov. 2, 1943 

